Improvement in heating-stoves



PATENT OFFICE.

ALONZO O. RAND, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN HEATING-STOVES.

Specification forming part of Letters Patent No. 119,719, dated October l0, 1871.

To all whom it may concern:

Be it known that I, ALONZO C. RAND, of the city of Chicago, in the county of Oook and State of Illinois,have invented an Improved Furnace for the more perfect combustion of coal, of which the following is a specification:

The nature of this invention relates to the more perfect combustion of bituminous and other coals in stoves, ranges, locomotives, Sac.; and the object is attained by an arrangement ofthe draught by which all the gases from the burning coal are kept at a high or constantly increasing temperature from the time of their birth till their combustion is perfect, in thev manner hereinafter described.

In the drawing, Figure I is vertical cross-section of a stove or furnace, showing the application of my device; Fig. II, a similar View, in plane, at right angles to Fig. I; Fig. III, a horizontal cross-section, in plane of line a' x, Fig. I 5 Fig. IV is a perspective view ofthe grate. Fig. V, a diagram, showing modifications in the arrangement of the central iiue.

A is the outer casing of a plain form of stove or furnace. B is the coal-magazine, provided with a central iiue, O, and closed top D. This top has a close-fitting door, d, on the two sides, for the admission of coal, and is also provided with small holes d1, protected by dauipers d2. Over the holes d1 are placed shields or guides cl3. Slide-doors E communicate with the top D, and a heat-dei'lector, F, is placed above the centra-l flue O. A grate, G, is furnished with an air-tube, H, projecting upward to or into the bottom of the central flue O. This air-tube has an independent communication with the outer air through the damper h and compartment h. I represents the escape-pipe, which is supplied with a damper, c', for the purpose of directing the heated products of combustion, when desired, downward through the pipe J into the radiator-box K, and thence upward, through the pipe L, into the direct-draught pipe I. M is the door, having a damper, m, through which ashes, Snc., are withdrawn.

The operation of the invention is as follows: The iire is first started by introducing kindlings and coal through the doors E and d and magazine B to the plate G, and applying a match beneath the said grate through the door M.A -The doors E and d having been closed before applying the match, and the damper il opened wide, a strong and direct draught is immediately established through the central flue O and escape- )ipe I. The damper h, through which air is supplied tothe air-tube H, should remain closed until the' coal becomes fully ignited. If desired, the magazine B may be entirely iilled with coal before lighting the fire. The damper-d.2 may be allowed to remain open until the whole body of coal in the magazine becomes moderately heated,

or for any length of time if a rapid fire is required. After the coal has become fully ignited the damper h, communicating with the heatingchamber h and tube H, may be opened in order to supply the gases and vaporsthe combustion of which has not been completed in passing through the incandescent fuel under the mouth ofthe central iiue O-with fresh-heated oxygen, and also, while the damper m remains open,to increase the draught through the layer of coal between the flue O and grate G. The damper t' may be closed afterthe fire is well started, and the heated results of combustion conducted through the radiator K, pipes J and L, as before described.

The principle upon which this` furnace is constructed is that of preventing the formation of smoke by increasing the temperature of the gases and vapors arising from incandescent coa-l from the time of their birth until the process of coinbustion is complete. Smoke is the result of coolingcand condensing the gases arising from burning fuel before the chemical change known as combustion is completed. As an illustration of this fact I may refer to the well-known result of a draught of cold air on rich coal-gas in producing smoke, while a current of heated fails to develop any smoke. Again, all know that a fire burns with less smoke after it has been kindled some time than when iirst ignited. The object of my invention is to apply this principle by so regulating the draught that all the gases formed Will be brought in contact with the hottest portion of the iire in such a manner that their temperature tained, from the time bustion is complete. v

The construction of the magazine in relation to the central iiue is such that thc layer of coal on the grate is sufiiciently thin to admit of a strong draught through the said layer into the central iiue and escape-pipe; and as the top of of their 'birth until comshall be increased, or at least main-b the magazine has a tight cover all the gases generated must pass through the burning coal under the mouth of the iiue. The fierce heat at this point would alone be nearly or quite suiicient to perfectly utilize the fuel; but, in order to make this result certain, an independent communication is opened with the outer air through the damper h. Air entering through this damper by reason of the suction created by the draught through the ilue C is carried around the compartment la in contact with the base and hottest part of the magazine, and then into the axial passage and tube H, through the red-hot coa-1, and discha-rging into the midst of the burning vapor in the central flue C, thus promoting a great increase of temperature. The deflector F, when used in stoves, assists in radiating' the heat by causing the column of heated products of combustion rising through the central iiue to impinge against the sides of the cylinder A. When the small holes d1 in the top l) are allowed to remain open, in order to induce a slight current through the mass of coal in theA magazine, all gases escaping from said holes are conducted, by the shield or guide-plates cl3, into the current of burning gas escaping from the central flue C.

The advantages I claim for this invention are of more than ordinaryimportance. The theory upon which most stoves, furnaces, &c., which have any reference to avoiding the escape of smoke have been built has been that of consuming it after it has been formed. The objection to this principle of operation is that when the gases are once allowed to cool the resultant smoke represents simply so much fuel, and as many units of heat will be required to again attain the te1nperature necessary for its pefect combustion as was originally required to convert it into a gaseous state.V Oxygen combines With carbon in two definite proportions, namely: six of the latter to eight of the former, producing carbonio oxide; or six of the latter and sixteen of the former, producing carbonic acid. The latter product is the resultant of complete combustion, involving a high temperature; the former, that of incomplete combustion, induced by a low temperature. Hence the necessity of maintaining a high temperature of the gases after being evolved from the coal.

Having thus fully described the objects, operation, and advantages of my invention, l will proceed to claim what I believe to be original with myself, and what I desire to secure by Letters Patent, namely:

l. The coal-magazine B, having closed top D and doors d, in combination With the ilue C, defiector F, and air-tube H, as set forth and described.

2. The air-tube H penetrating upward through the layer of coal on the grate G, and opening into the ilue C, substantially as and for the purpose described.

3. The heatdeilector F, when combined with the coal-magazine B having a central fine, C, for the object described.

4. The heating-compartment h', in combination with the tube H, grate G, flue C, and deiiector F, substantially as described.

In witness whereofI I have hereunto signed my name in the presence of two subscribing Witnesses.

A. (l. RAND.

Witnesses:

GEO. W. MIATT, J. B. GREIFENHAGEN. (151i) 

